[Precise SRU][PULL] fix XPS12 Cypress PS/2 trackpad

[Kamal Mostafa]

Bug reference:

	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1103594
	Cypress Trackpad mis-detected as "PS/2 Cypress Trackpad" on XPS 12

[IMPACT]

Due to a firmware change in the Cypress PS/2 trackpad, the driver fails
to properly detect the trackpad in the Dell XPS12 and possibly other models,
leaving the trackpad dysfunctional.

This patch -- a trivial backport from upstream -- fixes the detection glitch
in the driver.  The patch was cherry-picked into Raring.

[TESTCASE]

The patch was deployed as SAUCE in Raring some weeks ago, as well as in the
Sputnik kernel PPA for Q and P.  It has been verified to fix the problem in
all three.

[Regression Potential]

Low potential for regression: The change will only affect Cypress PS/2
trackpads (the problem and fix occur only after the trackpad has already been
detected as a Cypress), and it has been reasonably widely tested on Cypress
pads with the older firmware via the Sputnik PPA.

Thanks,

 -Kamal

-------- >8 ----------------------------------------------------

The following changes since commit 985689ad1c3211f4f3a9ce0e2371847320ba873f:

  UBUNTU: Ubuntu-3.2.0-40.64 (2013-03-25 15:41:43 -0500)

are available in the git repository at:

  git://kernel.ubuntu.com/kamal/ubuntu-precise.git cypress-xps12-sru1103594

for you to fetch changes up to 89623c06dc1531f602dbd4fc497298dfa5ebc583:

  Input: cypress_ps2 - fix trackpadi found in Dell XPS12 (2013-04-03 13:29:18 -0700)

----------------------------------------------------------------
Kamal Mostafa (1):
      Input: cypress_ps2 - fix trackpadi found in Dell XPS12

 drivers/input/mouse/cypress_ps2.c |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)